US Patent 5,931,746 which can be found using
http://patft.uspto.gov/netahtml/srchnum.htm describes a golf club
invented by Dr. Soong, based on his modeling of the dynamics of an
interacting golf club and ball. His mathematical papers on advanced
mechanics of sports events (striking a ball with a tennis racket, golf
club, etc or the flight of a thrown javelin) are available in the
technical literature. His several patents on some of the sports
objects can be found searching http://www.uspto.com. His math is a
bit beyond many of us.